The Cure
by FinnThePrince
Summary: When all of Ooo is thrown into chaos by a rogue mutation virus, Finn once again saves the day. But his turn in this has only begun, and he embarks on an adventure that might just destroy him; Will he give up the only things he has for the people he loves? When he finally finds family, humans, and love, will he have to give it all up just to save them all? T for Teen; Mild language
1. The Breakthrough

_It had been a year since it had happened. The Lich had let loose a viral monstrosity that could have wiped out all of Ooh. But it didn't wipe them out. Instead of doing what the Lich intended it to do, it mutated, changing anything it came in contact with into something horrible, deformed, kind of like a zombie. And there was supposedly "no cure". But me and Peppermint Dr., no longer a Butler, what with Peebles eaten away by the virus, a dark form of candy now, were going to find one. And we were so close… but I was about to have a nasty shock._

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I pushed my glasses farther onto my face, since they were slipping, and I sighed. Technically, I didn't need glasses, but they had belonged to the princess and gave me some form of solace. I chewed the inside of my mouth, growling a bit. The formula we were trying on the candy zombie mice wasn't working. I checked off the ones that had died, but one of them caught my eye. It wasn't so...deformed. It's candy wasn't so... malformed, as it was hot. It's skin wasn't so black, even so in spots that were ... candy-colored. And it was doing… well, regular mice stuff. Things that an Infected wouldn't do, like walking around the cage in confusion. I shined a light in its eyes, and it shrunk back, its retinas reacting slightly to the light.

"Good, good… eye-to-light reaction is repairing, reaction time is good… and aggression levels are lowering. Not to mention that the deformity and discoloration of the skin is disappearing as well..." I murmured. I opened the cage door, humming softly. It squeaked, and pointed to the name sign. I looked, and smiled.

"Well, hello, there, Science." I said, smiling more kindly. It had been a very long time since I had seen Princess Bubblegum's former rat, and… sort of my thunder-stealer. He had gotten the credit for saving the Candy Kingdom from the second wave of accidental zombies.I chuckled, remembering how it had all gone down, and picked him up gingerly. It squeaked, and licked my hand gently as one would touch a porcupine.

"How are youso passive right now? This makes no sense... I'll have to do some more testing." I said softly. I set the rat onto the table, watching it skirt around skittishly on the flat, slick surface. It sniffed the air, twitching its little button nose, and I watched in wonder as it skittered back to its cage and waited in front of it. I walked over to Dr. Peppermint, and tugged on his shirt.

"Doctor. One of the subjects is positive." I said, my face a bright wave of wonder and accomplishment. He whirled around, and looked at the calm, semi-deformed rat near the open cage.

"By Glob, Dr. Finn, you've done it! But…how?!" He stammered. I shrugged, chuckling a bit.

"All I did was add five to the quadrilateral effect of... hmm, I'll have to go over my notes again, I don't have it all memorized. I do know that all I had to do to finish it was put some of the Salve in the cure. It seemed to work. It was almost too simple to see, but I managed." I said. After everything had happened, I had immersed myself in science, so I could cure the populace and make everything right in the world again. As far as I knew, me and Butler were the only ones not affected by the Virus.

"Though I don't know why the Salve would have an effect on the patients, it doesn't have any special properties that we're aware of..." I murmured. I walked back over to the table, gathering my notes across the mess of stains and papers. Science nudged me as he walked past me, sniffling near the vials.

"A-amazing! Doctor, i think we may have a start to the cure!" Dr. Peppermint shouted happily. It was just then that Science chose to nibble on the hem of my shirt, whining softly.

"Oh. You must be hungry, I'm sorry, little guy…" I said softly. It nodded, and a spark of anger went through its filmed-over eyes. It bit my finger, and I jerked back a little, holding it in my mouth.

"Ow! Glob, Science, I could have just given you some candy!" It sheepishly looked away, the moment passing.I realized my mistake; it wasn't completely cured. I narrowed my eyes and face-palmed myself, aware of the consequences of my actions. It had bit me, which in turn had done what I had been trying to cure and prevent this entire time. Infect me with the Daerus. We called it that since it deformed the body into a demon-like structure.

"Oh, grib-grob…" I hissed, trying to keep a scowl off of my face. Sometimes, in times of extreme stress, I tended to get unnecessarily angry. I had narrowed it down to a teenager thing.

I put the rat back into its cage, put some candy pellets in there, and watched it nibble on the candy. It was eating, which was a good sign.

As soon as I looked at the bite on my finger, I realized that it was… gone. All that was left was a tiny angry scar. I wrapped my hand with a bandage, and started to scribble notes on how it affected humans on my research pad. It was interesting, how I was one of the most interesting species among the many hundreds in Ooo, and there was little to no information about me or my possible brothers and sisters.

"I'm going to see if i can perfect the formula. I don't think it worked all the way."

Dr. Peppermint looked my way and nodded, shrugging his shoulders, as if to say, 'Do whatever, you were the one who made the breakthrough.' He walked over to the table I was just at, grabbing the formula recreation I had made and swirling it around.

_5 days later_

I ran over to Dr. Peppermint, holding Science in my bandaged hand.

"I did it! I cured him!" I yelled. He whirled around, looking at the fully cured rat.

"My Glob, you did do it! We-we can save the Candy People, and everyone!" We danced around for a little bit, Science joining in for a little bit, doing a happy little jig in my hands. I teetered a bit, and steadied myself on the corner of the desk. Dr. Peppermint noticed, and looked at my hand. I was surprised he hadn't noticed all this time. It was quite obvious, the way my hand's reaction time had slowed with the rest of my body.

"Finn? Did it bite you before you cured it?"  
"Well… it was when I made the breakthrough. It was a tiny bite, and i don't think it did anything, so…" I said tentatively. He sighed, picking up the rat from my hands and putting a tiny lab coat around it.

"Finn, give me your hand. I want to see it." He reached for my hand, and I backed away.

"No way, man, I'm fine! Let's just get rid of the Zombies at the door. 'Kay?" I said nervously, frowning at my sudden evasiveness. That was another thing I would have to put down, the retraction from the cured or non-infected populace. He sighed, grabbing the dart gun.

"Fine. Whatever you say."

After everyone was cured, at least the ones that were at the door, we told them to stay in the room as we secured other places for them to stay. There were 14 Candy People in total. Not enough to rebuild. I frowned, returning to my desk, answering questions that the cured had about what was going on periodically. It sort of went like this:

Them: "What happened?"

Me: "You got sick."

Them: "Did we do anything bad?"

Me: "No."

I still wasn't feeling good as I checked myself for any other bites. My symptoms now included blurriness around the edges of my vision, evasiveness, and sudden bouts of anger. I had to be very careful with how I went on. But I didn't care. I would do whatever it took.

"Pep, I need a dart. I see Jake down there." I said, looking out the window at the hand stretching towards us. It had turned into a claw, the rest of his body black and malformed. From what I could see, his canines were massive, and the drool that escaped from his now-pointed snout seemed to have an acid-like affect on whatever it touched.

He nodded, handing me the dart gun. I aimed, teetered a bit, and shot. It hit him in the neck, and he immediately regressed back to mortal form; He curled up on the ground as his body immediately cured itself and reformed in the position and form that it's original was in, his black fur turning orange. He looked around at the zombies now starting to chase him and screamed, then stretched his way to the window I was at. He grabbed my shirt, pulling himself up, and I watched as he checked himself. I had recently adopted the philosiphy 'Check yourself before you wreck yourself', and found it ironic that he had too. He hugged me, tight enough to squeeze the air out of my lungs, and sat on a nearby chair.

"Dude! What the glob was going on down there?!"

"Zombies, idiot, zombies."

(Just a note: It came to my attention that some of the characters have Russian-sounding names, or did in their previous lives. (Ex: Simon Petrikov). So for noting's sake, they all speak Russian. If a character comes in with a different language, it's because of that.)

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**Thank you to those who have reviewed this story, TheFlameRose and Rivira! You guys are a great help! Keep watching for more chapters~ I might not be as active, since I'm using the library's computers.**

** Ciauo~**


	2. Problems

Jake sputtered, his hands shaking as he looked out the window at the Daeries. That was what they had decided to call them, since they were infected with the Daerus...

"But...but... I thought... aww man... did I... you know, kill anyone?" He asked, still shivering. I hugged my brother, a little too hard, and shook my head.

"Not that I know of, bro. But you're gonna have to keep an eye on the people that we cure. Oh, and help construct fences." I said, stepping away from my brother to give him a serious look. He sighed, groaning, his usual lazy self shining through as always.

"Fiiiiiine... I'll do it." He said, sauntering away grumpily to Dr. Peppermint, asking for a job. I ran my hands through my hair, sighing slowly and lengthily.

My heart skipped a beat as I looked out the window, and I stepped back, shivering. I could have sworn that I had saw Princess Bubblegum. Another shiver went up my neck, but this one was much more familiar. I turned around, smiling, and grabbed Marceline by the waist, giving the invisible vampire queen that devilish look of mine, enhanced by the lighting. She reappeared, and hissed, her eyes demonic. I noticed a bite on her arm, and I jabbed a needle into her skin, frowning. _I guess not everyone can avoid being bit by flying..._ I thought.

She shook her head, and I watched as her complexion returned to the normal pale. She looked at me with big, brown-red eyes, and smiled. The smile stayed there for a moment, with the two staring into each other's eyes, until Marceline decided to speak.

"Jeez, Finn, I don't know what I would have done without you." She said sarcastically, breaking the moment. I let go of her, smiling, and as I got ready to walk away, I felt a sharp pain in my chest, causing me to start to cough, hacking. She caught me as I fell, and lowered me onto the table. She looked at me anxiously, and I finally recovered, wiping blood from the side of my mouth. _Damn, it got worse..._ I thought, looking at the blood on the side of my hand as I pulled myself into a sitting position. She raised an eyebrow suspiciously, and grabbed one of the needles sitting on the table next to me. She tried to inject me, but I pushed her hand away, shaking my head weakly.

"The serum doesn't comply to the human genome. It'll destroy my DNA, killing me from the inside out. There's no cure for me." I smiled thinly, a tear falling down my cheek. She brushed it away, lip quivering.

"There has to be some way, something that can help." I was just about to shake my head when it hit me. _The ogre tears! _My eyes lit up, and she noticed the change automatically.

"What? What is it?" She said, grasping my hand lightly. I opened my mouth slightly, and smiled.

"The ogre tears at the tree-house. They could probably help. But I doubt they would cure me.." I said, fiddling with my fingers. She picked me up, and put me in a standing position.

"Who's the person who cured the candy people so far?" She said, putting her hands on her hips to look at me.

"Me..." I said, looking away. But she could tell that it was working.

"And who's the person who just cured a vampire without making them human?"

"Me."

"And who... who's the person who... captured my heart..." She murmured, her face turning a peach color. I guessed that was her definition of blushing. I blushed, my face turning a deep red, and I scuffed the floor with my foot. Me and Marcy had started going steady before all this had happened, but it never got really serious. Not until now.

"Me, and you know I love you." I said, smiling at her with my patent smile. She scoffed, ruffling my hat.

"Then it should be no trouble for you to get those ogre tears from your tree-house, with my help, of course. Come on, Bear-Hat."

I smiled, my heart melting at the sight of those brown and red eyes look at me with the kindness she reserved for those she loved. I grabbed her weakly, a little bit stronger than I had been before, and she opened the window, picking me up lightly and without much effort. Jake tried to grab us, but I glared at him and he just decided to let me and her be. _Who knows what went through his mind... eww_. I pushed the though out of my head, and looked down. She flew through the sky, the wind whipping her black hair like leaves in a windstorm, and she dodged flying Infected, weaving and dropping. I spotted the Treehouse, and hissed, looking at the number of Infected clustered around the door. There were obviously people holed up in there.

She let me down softly on the balcony, one of the overhanging tree branches that I had put a telescope on, and I wobbled, steadying myself.

"Whooh. That was intense." I said, chuckling. She set herself down on the branch, walking like she was on a cloud. There was a bump from inside, and a groan, and I ran in, breathing in sharply as I saw the human laying on the floor, with a vase on the floor next to him. I poked him with my sword, which I had not neglected to forget, and he mumbled, cursing very articulately. I watched as he opened his eyes, and stepped back as he shot up, grabbing his head and trying to reach for his bow at the same time. It was very funny, and so I forgot to put the filter on, ending up laughing. _I don't think he took it well..._ I thought, as he growled at my laugh. He pulled his brown bear hat off of his head, and I gasped, looking at him. Besides his black hair, he looked like... me! At almost the same time, though, we both said, with astonished expressions,

"Who the Hel are you?! " I pointed my sword weakly at him, and his gaze turned to my arm.

"So... you're one of them." He said, his eyes narrowing. Marceline shoved him into a wall, eyes red and demonic, and she spoke very slowly as she said, in a dark voice,

"I swear to God, if you do anything to hurt my man, you will feel the 9 levels of the Underworld on your ass. Do. You. Get. Me." He nodded shakily, eyes widening with fear. Her eyes returned to normal, and she sighed, grabbing me by the waist. As soon as she did, she turned my upside-down, chuckling.

"Now, Upside-Down boy, tell me where those tears are, so we can get you fixed up."

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**I'm**** sorry for all the fluff, I jut couldn't resist. If you guys want to, ask questions about me or about the story in general, and I'll answer them in this part of the story. Please, though, as not to clog up my Inbox, do it in a review.**

**~Ciaou!**


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